Lifting jack



T. c. PoME-Rov l July 24, mzzl LIFTING JACK Filed 0&15. 1I 1925 WMor/W Ccmffoy di, Ifuxvulww vv-owner@ Patented July 24, 1928.

UNITED sra'rnsV .TIMOTHY C. FOMERY, OF MINNEAPGLS, MINNESOTA..

LIFTING JACK.

Application led Catcher 1, 1925.

This invention relates to new and usetul improvements in lifting acks particularly adapted lfor use in lifting theaXles or wheels' ot automobiles, trucks, etc. and more particularly relates to such a device of the hydraulic type, using an inelastic tluid such as oil to transmit power in the operation of the jack. An object of this invention is to provide a hydraulic jack comprising a. stationary member having hollow ram or plunger reciprocally mounted therein, and provided with a simple valve mechanism controlled by the Aope'rating handle to regulate the flow oft fluid therein to lower the plunger.

The particular object of this invention, there-tore, is to provide an. improved hyidraulic jack which is an improvement over the lorm shown in the prior pending application by me and Carl E. Johnson, Se .Tal Number 7 34,730, filed August 28, 1924.

Other objects of the invention will. appear :from the following description and the accompanying drawings and will be pointed outI in the annexed claims.

In the accompanyingI drawings there has been disclosed a structure ilesigned to carry out the various objects ot' the invention, but it is to be understood thatthe` invention is not confined to the exactv features showin as various changes may be made within the scope ot the claims which follow.

In the accompanying drawing forming part ot this specification,

Figure 1 is a. vertical sectional view through the in'iproved jack showing the operating` handle in folded inoperative position;

Figure 2 is a detail sectional view through the lifting head of the jack showingl the valve mechanism actuated to release the pressure from the lower portion ot the jack;

F igure 3 is a` similar view showing the valve mechanism in normal position:

Figure l is a horizontal sectional Aview on the line 1f-l ot Figure 2 showing the comn'iunicat-ing duct between the intake tube and the annular groove in the tapered plug mounted in the lifting head;

Figure 5 is a detail View showing the tapered plug` removed 'trom the head;

Figure 6 is a detail sectioned view on the line 6-6 ot Figure 8 showinga modifiedA construction with 'the valve mechanisn'i in normal position.

Figure 7 is a similar view showingI the valve mechanism in open position to release Serial No. 59,909.

the fluid from the lower portion ot the jack: and l Figure 8 is a horizontal sectional view on the line 88 olf `Figure 7.

The body portion and the operating handle of the novel jack it'eatured in the invention are similar in construction and operation to the t'orm of jack shown in the above menw tioned pending application and it will therefore be unnecessary7 to describe same in detail.

As shown in Figure 1, the jack comprises a cylinder 10 mounted in .suitable hase 11 and having a hollow rain or plunger 12 reciprocally mounted therein. A packing nut 13.., having suitable packing 14 therein, is mounted upon the upper end ot the cylinder 10 to provide a leak-proof joint between the plunger and cylinder. An annular ring 15 is seated against thel upper end ot the cylinder 10 to provide a seat for the packing 1l. This ring also functions to limit the upward movement of the plunger 12 within the cylinder as a result ot the plunger being rediued in diameter to provide annular shoulder 16 adapted to engage the ring 15 when raised to the limit ot' upward movement.

A shouldered dise 17 is mounted upon the lower end o1 the plunger 12 to provide a closure therefor, and this disc is seeurel i clamped thereto by means of the intake and discharge tubes 18 and 19 having their upper ends seated in threaded sockets provided in the lifting head 21 as shown. "A suitable packing 22 is seated against the disc 17 and is secured thereto hy means ci a. plate 23 and the nuts 24 and 25 mounted in threaded engagement with the intake and discharge tubes 18 and 19. The nutI 24. is open as shown to provide a communicating passage between the lower portion and cylinder 10 and the discharge tube 19, while the nut 25 provides a closure `tor the lower end o1 the intake tube 18 to prevent the passage ol iiuid therethrough.

An important feature oft this invention resides in the novel construction et the valve mechanism mounted in the lifting head 21 of the jack. This valve mechanism consists primarily et two ball check valves which function to control the flow ot liquid between the interior of the plunger 12 and the lower portion of the cylinder 10. As shown in Figures 1, 2, and 3, a horizontal passage 26 is provided in the lifting hea-d 21 and has one end communicating with a tapered bore 27 in which a tapered plug 28 is rotat-ively mounted. This plug is preferably retained in the borev 27 by means of a compression spring 29 having one end bearing against a washer 31 seated against the hub 32 of the head 21, and having its opposite end seated against the inner face of a cap 33 which is retained upon the reduced end-portion 34 of the plug by mer-.ns of a pin 35. An annular groove 38 is provided in the plug 28 in alinement with the horizontal passage 26. A port 37 connects the groove 36 with the duct 38 axially provided in the plug having one end communicating with the intermediate handle section 39 mounted in a hub 41 provided in one end of the plug` as shown in Figures 4 and 5. A valve chamber 42, having a ball check valve 43 mounted therein, is arranged in the head 21 above the discharge tube 19 and communicates therewith through an upright passage 44 as shown. A compression spring 40 is mounted in the chanibcr 42 to retain the valve 43 in closed position. Thus it will be seen that when the valve 43 is open, communication will be established between the lower portion of the cylinder 10 and the intermediate handle section 39.

A similar check valve 45 is mounted in a valve chamber 46 directly above Jthe intake tube 18 and similarly communicates therewith through an upright passage 47 as shown in dotted lines in Figures 1, 2, and 3. This valve is normally held against its seat by means of a compression spring 48 in a manner similar to that shown and described with reference to the valve 43. Referring to Figure 4, it will be noted that the intake tube 18, and therefore the upright passage 47, are offset from a line drawn through upright passage 44 of the tube 19 and the annular grooves 36 of the plug 28. The tube 18 is preferably oilset as described above in order to simplify the construction of the valve chamber 48 and also to eleminate interference between the valve ports and passages provided in the head 21. The horizontal passage 26 leading from the discharge tube 19 communicates withv the valve chamber 46 through a duct 49 as shown in Figures 1, 2, and 3, so that when the pump is actuated the fluid may be drawn from the interior of the plunger 12 into the passage 26, and thence into the annular groove 36 communicating with the intermediate handle section 39.

The means provided for pun'lping the fluid from the interior of the plunger 12 and forcing it beneath the packing or piston 22 to raise the jack, preferably consists of a pump mounted ina section of the operating handle. The form of operating handle shown in connection with this jack consists of the intermediate section 39 and a pump section 51 having a pivotal connection with the section 39 through a tapered joint 52 as shown in Figure 1. A pump rod 53 is reciprocally mounted within the pump section 51 and is operable by means of hand grip 54 provided thereon as shown. Suitable means such as the stulling box 55 are provided upon the pump section of the handle to prevent oil leakage therefrom when the ack is in operation and when it is stored away in a tool box or similar place.

W hen the pump rod 53 is outwardly drawn from the pump section 51 of the jack handle, oil will be drawn from the interior of the plunger 12 into the intake tube 18 through a duct 56, thence through the upright passage 47 and into the valve chamber 46, the flow ofV oil unseating the valve 45 and the oil flowing through the duct 49 into the horizontal passage 26, thence into the groove 36, port 37, duct 38, intermediate handle section 39, and into the pump section 51. Upon the return or inward stroke of the pump rod 53, the oil or fluid drawn into the pump section of the handle, will be forced ther-etre i bacl-:jintoithe horizontal passage 26 .t the ball check valve thereby causing it to open and permit the oil to flow into the discharge tube 19 and thence into the lower portion of the cylinder 10 with the resultant raising of the plunger' 12 within tl e cylinder. Such flow of oil through the lifting head 21 will cause the check valve 45 to be seated so that all of the liquid drawn into the pump will be forced into the lower portion of the cylinder beneath the biston. Thus, it will be noted that continued reciprocal movement of the pump rod 53 will cause the liquid contained within the hollow plunger 12 to be forced into the lower portion of the cylinder beneath the piston, thereby causing the plunger to rise until the movement of the pump rod 53 is interrupted, or, until the annular shoulder 16 of the plunger engages the stop rod 14 adjacent the upper end of the cylinder.

The means provided for releasing the fluid under pressure from the lower portion of the cylinder and permitting it to tlow back into the interior of the plunger, as when lowering the jack, preferably consists of a thrust member 57 mounted within the horizontal passage 26 and having one end adapted to engage the valve 43 as particularly shown in .Figure 2. The opposite end of this thrust member is adapted to be engaged by a cani 58 secured to the tapered plug 28 in alineinent with the thrust member. This cam, therefore, is preferably seated in the bottom of the annular groove 36 as shown in Figures 1, 2, and 3, and is relatively narrower than the groove 36 so as to permit the oil to flow thereby7 when the valve is open. 1n Figures 1 and 3 the thrust member 47 is shown out of engagement with the cam 58 and theI check valve 43 is therefore seated by the action of the springI 40. Figure 1 illustrates the position of the handle when folded against the body of the jack as when placed in a tool box or other storage place; while Figure 3 illust-rates the approximate angle of the handle with relation to jack body when the pump is being operated to raise the plunger. Figure 2 illustrates the posit-ion of the intermediate handle section 39 when it is desired to open the check valve 43 to permit the fluid to flow from the lower portion of the cylinder back into the interior of the plunger as when lowering the jack. A groove or recess 59 is provided in the periphery of the tapered plug 28 and leads from the anna lar groove 86 to a port 61 having its lower end communicating with the upright pa,- sage 17, as particularly shown in Figure el. This groove 59, it is tok be understood, communicates with the port 61 only when the am 58 engages the thrust member 57 to open the check valve 48. Thus it will be noted by reference to Figures 2 and 4, that when the check valve 4.3 is in open position as shown in Figure 2, the groove 59 will be in registration with the port 61, thereby establishing communication between the discharge tube 19 and the intake tube 18 with the result that the liquid under pressure in the lower portion ofthe jack will flow therefrom through the discharge tube 19, head 21, through the intake tube 18 and back into the interior of the plunger 12. .By this simple valve mechanism, therefore, it will readily be seen that the lowering of the jack may be simply and conveniently ail'ected by simply oscillating the intermediate handle section 39 until the groove 59 is brought into registration with the inclined port 61 as shown in ligures 2 and fl. The downward movement of the plunger may thus be controlled or interrupted at will by simply oscillating the intermediate handle section 89 as above described.

ln devices of this type it is usually necess sary that means be provided for admitting air into the hollow plunger 12 during the lifting operation of the jack and also that air thus drawn into the plunger may be Ypermitted to escape therefrom when the jack is being lowered to its normal position. A vent hole 62 is therefore provided in the upper portion of the hollow plunger 12 at a point slightly below the lower face of the lifting head 21, shown in Figures 1, 2, and 3. This vent hole is so located that when the` plunger 12 is in its normal retracted position, as shown in Figure 1, it will be moved downwardly into the packing nut 13 of the cylinder, thereby closing the vent and thus preventing the 'liquid wit-hin the plunger from leaking out of the jack. ln the operation of the j ack1 as soon as the plunger rod is actuated and the plunger' begins to rise within the cylinder, the vent 62 will move out of the packing nut 13 so that air may be drawn into the plunger valve mechanism in connection with a jack of the type herein shown, the operation of such a jack will be positive and fool-proof. lts construction also very simple and inexpensive and all parts are so arranged and assembled that they may readily be removed for repairs or replacement when necessary, thereby providing a mechanism which may be manufactured at a minimum cost.

Figures 6, 7, and 8 illustrate a modified construction wherein a check valve 43a is mounted to be engaged directly by the cam 58 when it is desired to' release the liquid, under pressure, rrom the lower portion of cylinder and permit it to return to the interior of the plunger 12. In the constructioihere shown, a supporting member 68 is interposed between the spring lOL and the plug 6a to provide a seat or support for the spring. This supporting member and also the springa and valve 43a are mounted in a passage G5 which communicates with the discharge tube 19 through the upright passage del as ihown. A valve cage 66, having a check valve 67 mounted therein and held against its seat by a spring 68, is mounted in a passage 65) substantially below the check valve a3, as shown in Figures 6 and 7.-

The valve chamber in th-e cage 6G communin Gates with the annular groove 36 of the plug 28 by means of a duct 69. A port 71 is provided in the opposite end of the cage 66 which communicates with the upright passage 17, leading from the intake tube 18, and also with an inclined port 72 having its upper end communicating with the tapered bore in which the plug 28 is mounted, in such a manner as to register with the groove when the Cam 58 is in valve-opening position as shown in Figure 7.

In the construction here shown, the oil is drawn from the intake tube 18 into the valve cage 66 and thence into the annular' groeve it being understood that when the pump is being actuated the intermediate handle section 89 of the pump handle will be positioned as shown in Figure 6, or in such a manner that the cam 58 will be out of engagement with the ball check valve 43a. During the suction stroke of the pump, the check valve 67 will open to permit the flow of oil, and during the pressure stroke of the pump, the valve 67 will be seated and the check valve kl13* will be opened to permit` the liquid to flow from the pump through the passage 65 and into the discharge tub-e 19 to cylinder and with the interior of the lowerportio'n of the cylinder beneath the piston. lhen it is desired to lower the jack, the intermediate handle section 39 will be moved to the position shown in Figure 7, thereby causing the cam 58 to engage the ball valve 43a with theresult that it will be opened to permit the liquid under pressure in the lower portion of the cylinder to flow through' thelopcn valve and into the annular groove 3G, from whence it will flow through the groove 59 and inclined duct 72 into the upper end of the intake tube 18 and back to the interior of the plunger.

I claim my invention l. A lifting jack comprising in combination, a cylinder. adapted to contain an inelastic fluid, a hollow plunger movable in said cylinder, a lifting head on said plunger having fluid passages' connecting it with said said plunger, valves in said passages for controlling fluid flow therethrough when the plunger is raised, a pump having a pivot in sa-idhead, a by-pass in said pivot and aid head for permitting the return of the fluid from the cylinder lto the interior of said plunger, and means operable by rotation of said pivot to open one of said valvesI to allow the fluid in the cylinder to flow through aid by-pass and return to said plunger to lower the jack.

2. A lifting jack conlprising in combination, a cylinder adapted to contain an inelastic fluid, a hollow plunger movable therein,

a lifting head on said plunge-1' having fluid passages connecting it with said cylinder and with the interior of said plunger, a check valve inl each passage adapted to control fluid flow therethrough when the plunger is raised, a plug valve pivotally mounted in said head and communicating with said pas.- safres, a pump operatively connected with said plug valve, a by-pass for permitting the return of the fluid from said cylinder to said plunger, amember in one of said passages adapted to engage the check valve mounted therein, and means on said plug valve for actuating said member to open its complementary valve, upon rotation of said plug valve, whereby the fluid in said cylinder is permitted to flow through said by-pass and return to said plunger to lower the jack.

3. A lifting jack comprising in combination', a. cylinder, a hollow plunger movable therein, aninelastic pressure fluid, a lifting headon the plunger, check valves mounted in saidhead, means for connecting each valve with one side of the plunger, a tapered plug pivotally mounted in thel head and having a pump operatively connected therewith, an lannular groove in said plug communicating with said valves, a by-pass in said plug and said headfunctioning to provide a. passage for returning the fluid from the cylinder to the plunger, and a cam secured to :Laid plug and rotatable therewith to open one of said valvesto permit the fluid in the cylinder' to return through said by-pass to the plunger, when the lifting head is being lowered.

4. A lifting jack comprising in combination, a cylinder, a. hollow plunger movable therein, an inelastic pressure fluid, a lifting head on the plunger, check valves in said head, means for connecting each valve with one side of the plunger, a tapered plug rotatably mounted in said head and having a pump operatively connected therewith, an annular groove in said plug, a communicating iaffsage between said groove and one of said valves, a by-pass in said plug and said hea-d functioning to provide a passage fer returning the fluid from the cylinder to the plunger, means in said communicating passage adapted to be engaged by means on said plug valve, when the latter is rotated a predetern'iined distance, to cause the valve ii said passage to be opened to permit the passage of fluid from the cylinder through said by-pass and into the interior of the plunger to lower the jack.

5. A lifting jack comprising in combination, a cylinder, a plunger operable therein, an inelastic. pressure fluid, a lifting head on the plunger, a plug valve rotatably mounted in the head and having fluid' duets connecting it with each side of the plunger, a check valve in each duct, a pump operatively7 connected with said plug valve, an annular groove in the periphery of said plug, noi'- mally closed by-pass connecting said annular groove wit-h the interior of said plunger,` a thrust member movably mounted in one of said ducts and normally projecting into said groove, and a cam secured to said plug and adapted to actuate said thrust member, when the plug is rotated, to cause the check valveadjacent to said member to open and permit the fluid in the cylinder to ret-urn from the cylinder to the interior of said plunger, through said by-pass.

6. A lifting head comprising in combination, a cylinder having a plunger operable therein, a. reservoir, a lifting head on the plunger, a plug valve in said head, a pump connected with said plug valve and adapted to rotate the latter, passages in said head connecting said plug valve with the cylinder' and the reservoir, a. check valve in each of said passages, a cam on the plug valve, means in one of said passages actuable by said cam to open the check valve in said pas TIMOTHY C. POMERGY.

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